1. Field of the Invention
The present invention relates to a technology which is required to obtain feature information from spatial geometric data of a target region.
2. Description of Related Art
In the past, the demand was concentrated on industrial stationary robots. On the contrary, in recent years, research on mobile robots is actively in progress along with an increase in the demand for the household robot market.
A variety of research is being conducted on the improvement of the performance of the mobile robots. One of core technologies of this research is exemplified by a technology of finding a feature in a space. For example, the finding of a feature in a surrounding space is indispensable in order for a robot to move around or recognize an object in a real life. To this end, a proper feature is required to be extracted from data observed from various items of sensor information.
In particular, several environmental factors should be taken into consideration in a space where people do activities unlike a factory where industrial stationary robots are present. Typically, unlike an outdoor environment, an indoor space can be classified into the following three factors: (1) structure, (2) object, and (3) dynamics (see FIG. 1A). As used herein, the term “structure” refers to a constantly stationary portion such as a wall surface in the indoor space. The structure means a completely static element having no movement because it is not changed as long as a factor of changing the internal environment like the interior construction does not occur. The structure defines a volume of the indoor space. Thus, in the case where the structure is observed in the indoor space, there is a high possibility that the structure would be disposed at the outermost portion of the indoor space.
In addition, as used herein, the term “object” refers to a temporarily static element or a potentially dynamic element which maintains a temporarily static state in a situation where the object is placed as it is while being present in the indoor space, but which may be changed in the position or direction thereof within a corresponding time period upon the lapse of a short time period ranging from several seconds to several hours.
In the meantime, as used herein, the term “dynamics” refers to a dynamic element which is present in the indoor space and whose motion occurs at a current time point.
However, conventional localization and object recognition technologies are implemented in an environment totally different from actual environment requirements which require a dynamic environment including a potentially dynamic element or a dynamic element having an object or a dynamics in that they are implemented under the control of a static environment. In other words, because the static environment including only the structure is based on the assumption that any extracted feature is stationary in an environment or is present under a controlled motion, there exists a possibility that an object or a person which is not controlled under the dynamic environment will move in an unpredicted direction. Thus, there is a problem in that it is difficult to directly apply the conventional localization and object recognition technology to the dynamic environment similar to a real environment.
In order to solve such a difficulty, there is needed either a technology of grasping the structure whose position will not be changed in the dynamic environment or a technology of grasping the object or the dynamics whose position will be changed in the dynamic environment, i.e., a technology of capable of separating the static element and the potentially dynamic element or the dynamic element.
An example of such a structure can include wall structure information. When the wall structure information is carefully observed in any space, most of the wall structure, i.e., the structure is positioned at an outer portion. In other words, it can be seen that when an environment is observed in an indoor space, the wall structure, i.e., the structure is positioned behind the dynamics or the object.